This invention relates generally to the field of telecommunications, and more particularly to transitioning a standards-based card into a high availability backplane environment.
Many telecommunications devices include backplanes for transmitting digital information between components of the devices. For example, a telecommunications switching system might include a backplane and associated data bus for transmitting digital data representing voice or data signals between cards associated with incoming and outgoing ports. Typically, such a system would also include a bus to allow these cards to communicate appropriate commanded, control, and administrative information with each other and with other components during operation of the system. Successful operation of the system will in many instances depend heavily on the ability of these communications mechanisms to satisfy the typically stringent availability, bandwidth, flexibility, and other requirements placed on the system.
As the telecommunications industry continues to dominate the growth of the global economy, satisfying availability, bandwidth, flexibility, and other requirements placed on switching and other telecommunications systems has become increasingly important. High availability may be generally considered as exceeding 99.999 percent availability, amounting to less than approximately five minutes of xe2x80x9cdown timexe2x80x9d during each year of operation, and generally: requires that a system be able to detect and to autonomously handle certain faults, such as total or partial failure of a card, without immediate human intervention. Providing high availability is often a de facto if not explicit competitive requirement for many telecommunications manufacturers.
However, standards-based communications techniques are inadequate to meet requirements placed on many high availability systems. For example only and without limitation, data buses based on the Computer Telephony (CT) bus structure specified in the Enterprise Computer Telephony Forum (ECTF) H.110 standard, on a MITEL Serial Telephony (ST) bus structure, or on other serial data bus structures are inadequate for high availability applications. Similarly, command, control, and administrative buses based on a Peripheral Component Interconnect (PCI) or on a compact PCI (cPCI) bus structure lack one or more attributes important within a high availability backplane environment. Among other deficiencies, none of these buses provides an appropriate combination of redundancy, hot insertion, fault detection, fault isolation, and fault recovery. Standardsbased and other off-the-shelf cards generally provide the benefits associated with widespread commercial availability; including reduced cost relative to custom solutions. However, because such cards often include a data bus, a command, control, and administrative bus, or both types of data buses based on the bus structures discussed above, standards-based cards have been unsuitable for operation within high availability backplane environments of modern telecommunications systems.
According to the present invention, the disadvantages and problems associated with operation of standards-based cards within high availability backplane environments have been substantially reduced or eliminated.
According to one embodiment of the present invention, a telecommunications device includes a backplane with an associated high availability backplane environment. A transition card coupled to the backplane transitions a standards-based card supporting a Peripheral Component Interconnect (PCI) administrative bus into the high availability backplane environment. The transition card may also help transition either a Computer Telephony or a Serial Telephony serial data bus into the high availability backplane environment. In a more particular embodiment, the transition card may support a control bus, a synchronization bus, a reset bus, an isolate bus, and a power bus that each support at least one high availability characteristic not associated with the PCI bus. In another more particular embodiment, the transition card may provide at least some redundancy, hot insertion, fault detection, fault isolation, and fault recovery capabilities not associated with the PCI bus.
The present invention provide a number of important technical advantages. Unlike data buses based on a CT or ST bus structure, unlike command, control, and administrative buses based on a PCI bus structure, and unlike other standards-based buses, the buses and associated operation of the present invention provide a suitable combination of redundancy, hot insertion, fault detection, fault isolation, and fault recovery, making them collectively appropriate for use in high availability backplane environments. According to the present invention, standards-based and other off-the-shelf cards are readily transitioned into a high availability backplane environment to provide benefits of standards-based cards, such as widespread commercial availability and reduced cost, without sacrificing high availability characteristics. With the present invention, faults that arise in connection with standards-based cards and their buses are detected, isolated, and responded to such that the faults are prevented from propagating to other components in the system. Unaffected components may continue operating substantially uninterrupted and maintaining substantial data integrity despite the fault. As a result of these and other important technical advantages, the present invention is particularly well suited for incorporation in a variety of switching and other modern telecommunications devices.